Field Testing & Calibration
Log launches, measure performance, and calibrate your predictions
🖌 Log a Launch
Weather Conditions
Field Measurements
📋 Launch Records
| # ↕ | Date/Time ↕ | Launcher | Rocket | PSI ↕ | Angle ↕ | Height ft ↕ | Dist ft ↕ | Time s ↕ | Spin | Status | Actions |
|---|
🔧 Register Launcher
📍 Saved Launchers
No launchers registered yet.
🚀 Register Rocket
🚀 Saved Rockets
No rockets registered yet.
⏱ Stopwatch Altitude Estimator
📏 Altitude Calculator
📝 Quick Reference & Tips
What you need:
- A phone inclinometer app, or print the clinometer below
- A measuring tape or pre-measured baseline
- A clear sightline to the rocket apex
Best practices:
- Stand perpendicular to the flight path - not behind or in front of the launcher
- 100+ ft baseline works well for most rockets
- Have your inclinometer ready before launch
- Track the rocket visually and lock in the reading at apex
- Have a second person track while you operate the launcher
Accuracy notes:
- At 100 ft baseline, 1° error ≈ 3-5 ft height error
- Longer baselines reduce error at low apex angles
- Phone inclinometers: ±0.5° typical accuracy
- Avoid baselines under 50 ft - errors compound at steep angles
📋 Altitude Lookup Table
Pre-computed heights (ft) for common distances and angles. Print this to take to the field.
🔧 Printable Clinometer
Print this clinometer, cut it out, and attach a string with a small weight (washer, nut, or fishing sinker) through the center hole as a pendulum. Sight along the top edge at the rocket's apex - the pendulum hangs straight down and the string crosses the angle scale.
⏱ Flight Timer & Drag Analysis
📈 Drag Analysis
Enter the measured height (from Altitude Tools tab) to compute velocity and drag estimates from your timing data.
💡 Physics Notes
Ascent phase: Rocket decelerates under gravity + aerodynamic drag. Higher launch velocity means drag force is large initially.
Descent phase: Rocket accelerates under gravity, opposed by drag. Eventually reaches terminal velocity where drag = weight.
Key insight: If ascent time < descent time, the rocket has significant drag (it slowed down faster going up than gravity alone would account for). The ratio of times tells us about the drag coefficient.
Terminal velocity estimate:
V_t = 2 × H / t_descent
(approximation assuming terminal velocity reached quickly)
Average launch velocity:
V_launch ≈ 2 × H / t_ascent
(approximation - actual is higher due to drag losses)
📋 Timed Flights
| # | Ascent (s) | Descent (s) | Total (s) | Est. V_t (fps) | Est. V_launch (fps) | Height (ft) | Actions |
|---|
No timed flights yet. Use the timer above to record flights.
📊 Rocket Performance Comparison
📈 Pressure vs Max Height
📈 Pressure vs Landing Distance
⚖ Rocket Mass vs Max Height
⏱ Flight Time Distribution
🎯 Calibration: Theory vs Measured
Compare calculator predictions with field measurements to derive correction factors and improve accuracy over time.
Height Calibration
Distance Calibration
Velocity Calibration
📈 Calibration History & Correction Factors
No calibration entries yet.
🗓 Session History
No sessions recorded yet.